First clinical trial using viruses to fight cancer begins

The world's first clinical trial for viral cancer therapy has just been launched by the NCIC Clinical Trial Group (CTG).

The group, located on the Queen's University campus, is the largest cancer clinical trial co-operative in Canada.

"When normal cells become cancerous, it's like they are making a deal with the devil," Dr. John Bell, one of the doctors who discovered and is developing the therapy, said in a news release.

"They acquire genetic mutations that allow them to grow very quickly, but these same mutations also make them more susceptible to viruses."

There are certain viruses that exploit this weakness in cancer cells. Two of them, the Maraba virus (MG1MA3), derived from Brazilian sandflies, and Adenovirus (AdMA3), derived from a common cold, will be combined for the trial.

The viruses have been engineered to not only destroy cancer cells, but to trigger an immune response so that the body recognizes the cancer as a threat.

"This is a whole different way of trying to attack cancer cells," said Dr. Janet Dancey, director of NCIC CTG and professor of Oncology at Queen's.

The theory that viruses may destroy cancer cells has been around for more than a century. It was sparked when doctors observed that some cancer patients, after they had a viral infection, miraculously recovered. But only in recent years has viral therapy been rigorously developed and tested.

Along with Bell, doctors David Stojdl and Brian Lichty investigated the therapy, ever since they worked together at the Ottawa Hospital nearly 15 years ago.

"Every treatment we have today "¦ is because cancer patients have volunteered to participate in the clinical trial," Dancey said.

"It's so amazing to me when people -- at what is often a very difficult time in their life -- volunteer to take part in the clinical trial," she continued. "Hoping that they might benefit, but also hoping their efforts in the trial might benefit other people -- and that's how we make progress."